Screening tests for blood donations are based upon sensitivity, cost-effectiveness and their suitability for high-throughput testing. Enzyme immunoassay (EIAs) for hepatitis C virus (HCV) antibodies were the initial s...Screening tests for blood donations are based upon sensitivity, cost-effectiveness and their suitability for high-throughput testing. Enzyme immunoassay (EIAs) for hepatitis C virus (HCV) antibodies were the initial screening tests introduced. The ”first generation“ antibody EIAs detected seroconversion after unduly long infectious window period. Improved HCV antibody assays still had an infectious window period around 66 d. HCV core antigen EIAs shortened the window period considerably, but high costs did not lead to widespread acceptance. A fourth-generation HCV antigen and antibody assay (combination EIA) is more convenient as two infectious markers of HCV are detected in the same assay. Molecular testing for HCV-RNA utilizing nucleic acid amplification technology (NAT) is the most sensitive assay and shortens the window period to only 4 d. Implementation of NAT in many developed countries around the world has resulted in dramatic reductions in transfusion transmissible HCV and relative risk is now < 1 per million donations. However, HCV serology still continues to be retained as some donations are serology positive but NAT negative. In resource constrained countries HCV screening is highly variable, depending upon infrastructure, trained manpower and financial resource. Rapid tests which do not require instrumentation and are simple to perform are used in many small and remotely located blood centres. The sensitivity as compared to EIAs is less and wherever feasible HCV antibody EIAs are most frequently used screening assays. Efforts have been made to implement combined antigen-antibody assays and even NAT in some of these countries.展开更多
The two most common techniques available for diagnosis of malaria in Nigeria are microscopy and rapid diagnostic tests (RDTs). However, in diagnosing asymptomatic Plasmodium parasitaemia among donors, the preferred te...The two most common techniques available for diagnosis of malaria in Nigeria are microscopy and rapid diagnostic tests (RDTs). However, in diagnosing asymptomatic Plasmodium parasitaemia among donors, the preferred technique should not only be timely but must not compromise diagnosis. It should be more sensitive with minimal chances of false negative results. This study was carried out to compare microscopy and RDTs as effective tools for diagnosis of Plasmodium parasitaemia among blood donors in Port Harcourt. There were 200 donors involved in the study among which 135 (67.5%) tested positive and 65 (32.5%) tested negative on microscopy whereas 30 (15.0%) tested positive and 170 (85.0%) tested negative to RDT with a statistically significant difference between both techniques. Data were analysed using the statistical package epi-info version 7.02. We therefore recommend that microscopy using giemsa-stained blood films remain the method of choice for diagnosis of Plasmodium parasitaemia among blood donors to prevent the spread of transfusion malaria.展开更多
目的基于血液筛查核酸检测反应性献血者的HBV感染的确认,探讨核酸检测反应性献血者的归队策略。方法联合应用自建的高灵敏度核酸检测体系、血液核酸筛查等多种核酸检测(NAT)方法,并结合血清学检测、献血者随访,对核酸检测反应性(NAT-yie...目的基于血液筛查核酸检测反应性献血者的HBV感染的确认,探讨核酸检测反应性献血者的归队策略。方法联合应用自建的高灵敏度核酸检测体系、血液核酸筛查等多种核酸检测(NAT)方法,并结合血清学检测、献血者随访,对核酸检测反应性(NAT-yield)献血者中的HBV感染进行确认和感染状态识别。依据确认的HBV感染血浆样本,比较不同确认方法、确认指标或指标组合对HBV感染确认的效果。结果2010年11月—2021年2月,在血液筛查检出的876位NAT-yield献血者中共确认HBV感染者511人(OBI 451人,急性早期HBV感染者27人,不能确认感染者33人,无感染者30人,不能确认HBV感染者335人)。采用单检系统对混检系统检出的HBV感染血浆进行复测的检出率为96.6%,明显高于混检系统对单检系统检出的HBV DNA反应性(HBV DNA R)组和鉴别试验无反应性(NDR)组的复测检出率(76.4%和55.7%)(P<0.05)。NDR样本在模式2(ID×5+鉴别×2)下复测检出率(65.2%)高于模式1(ID×2+鉴别×1)(39.2%)(P<0.05);2种单检复测模式下的HBV DNA R样本复测检出率无明显差异(P>0.05),但均明显高于NDR样本(P<0.05)。回溯OBI献血者既往NAT数据,有46%经历多次NAT检测而未能检出。有59.1%OBI献血者随访检不出HBV DNA。OBI献血者中抗-HBc+占比为90.2%,单独抗-HBc+为49.2%,远高于不能确认感染组(P<0.05);HBeAg、抗-HBe和抗-HBc IgM在OBI和不能确认感染组中的比例极低且无差异(P>0.05)。结论近60%的NAT-yield献血者可以确认HBV感染。为保证献血者归队的安全性,需要更高灵敏度的HBV DNA确证技术提高HBV感染的确认率。抗-HBc是NAT-yield献血者OBI风险排查和归队评估最重要的血清学指标。展开更多
文摘Screening tests for blood donations are based upon sensitivity, cost-effectiveness and their suitability for high-throughput testing. Enzyme immunoassay (EIAs) for hepatitis C virus (HCV) antibodies were the initial screening tests introduced. The ”first generation“ antibody EIAs detected seroconversion after unduly long infectious window period. Improved HCV antibody assays still had an infectious window period around 66 d. HCV core antigen EIAs shortened the window period considerably, but high costs did not lead to widespread acceptance. A fourth-generation HCV antigen and antibody assay (combination EIA) is more convenient as two infectious markers of HCV are detected in the same assay. Molecular testing for HCV-RNA utilizing nucleic acid amplification technology (NAT) is the most sensitive assay and shortens the window period to only 4 d. Implementation of NAT in many developed countries around the world has resulted in dramatic reductions in transfusion transmissible HCV and relative risk is now < 1 per million donations. However, HCV serology still continues to be retained as some donations are serology positive but NAT negative. In resource constrained countries HCV screening is highly variable, depending upon infrastructure, trained manpower and financial resource. Rapid tests which do not require instrumentation and are simple to perform are used in many small and remotely located blood centres. The sensitivity as compared to EIAs is less and wherever feasible HCV antibody EIAs are most frequently used screening assays. Efforts have been made to implement combined antigen-antibody assays and even NAT in some of these countries.
文摘The two most common techniques available for diagnosis of malaria in Nigeria are microscopy and rapid diagnostic tests (RDTs). However, in diagnosing asymptomatic Plasmodium parasitaemia among donors, the preferred technique should not only be timely but must not compromise diagnosis. It should be more sensitive with minimal chances of false negative results. This study was carried out to compare microscopy and RDTs as effective tools for diagnosis of Plasmodium parasitaemia among blood donors in Port Harcourt. There were 200 donors involved in the study among which 135 (67.5%) tested positive and 65 (32.5%) tested negative on microscopy whereas 30 (15.0%) tested positive and 170 (85.0%) tested negative to RDT with a statistically significant difference between both techniques. Data were analysed using the statistical package epi-info version 7.02. We therefore recommend that microscopy using giemsa-stained blood films remain the method of choice for diagnosis of Plasmodium parasitaemia among blood donors to prevent the spread of transfusion malaria.
文摘目的基于血液筛查核酸检测反应性献血者的HBV感染的确认,探讨核酸检测反应性献血者的归队策略。方法联合应用自建的高灵敏度核酸检测体系、血液核酸筛查等多种核酸检测(NAT)方法,并结合血清学检测、献血者随访,对核酸检测反应性(NAT-yield)献血者中的HBV感染进行确认和感染状态识别。依据确认的HBV感染血浆样本,比较不同确认方法、确认指标或指标组合对HBV感染确认的效果。结果2010年11月—2021年2月,在血液筛查检出的876位NAT-yield献血者中共确认HBV感染者511人(OBI 451人,急性早期HBV感染者27人,不能确认感染者33人,无感染者30人,不能确认HBV感染者335人)。采用单检系统对混检系统检出的HBV感染血浆进行复测的检出率为96.6%,明显高于混检系统对单检系统检出的HBV DNA反应性(HBV DNA R)组和鉴别试验无反应性(NDR)组的复测检出率(76.4%和55.7%)(P<0.05)。NDR样本在模式2(ID×5+鉴别×2)下复测检出率(65.2%)高于模式1(ID×2+鉴别×1)(39.2%)(P<0.05);2种单检复测模式下的HBV DNA R样本复测检出率无明显差异(P>0.05),但均明显高于NDR样本(P<0.05)。回溯OBI献血者既往NAT数据,有46%经历多次NAT检测而未能检出。有59.1%OBI献血者随访检不出HBV DNA。OBI献血者中抗-HBc+占比为90.2%,单独抗-HBc+为49.2%,远高于不能确认感染组(P<0.05);HBeAg、抗-HBe和抗-HBc IgM在OBI和不能确认感染组中的比例极低且无差异(P>0.05)。结论近60%的NAT-yield献血者可以确认HBV感染。为保证献血者归队的安全性,需要更高灵敏度的HBV DNA确证技术提高HBV感染的确认率。抗-HBc是NAT-yield献血者OBI风险排查和归队评估最重要的血清学指标。
